PAKT II. 

 THE DOG IN DISEASE. 



GENERAL PRINCIPLES. 



The processes or functions of the animal body in a 

 natural condition, or in health, have been considered in 

 one brief chapter (page 10), which it might, at this stage, 

 be worth the reader's while to review. 



We have now to consider those deviations from the 

 normal which constitute what is termed " disease," and, 

 before undertaking the discussion of specific forms of dis- 

 ease, it may be well to consider some of the main principles 

 which underlie the subject. 



Causation. — The environment may be regarded as the 

 entire collection of conditions under which an animal 

 lives, life being the resultant of the action of the environ- 

 ment on the organism. If this be unfavorable, disease 

 results, and the unfavorable factor is termed the cause of 

 the disturbance. Causes are divided into 'predisposing and 

 exciting. Thus, everything that tends to lower the vitality 

 of the animal is a predisposing cause of distemper in the 

 dog, while a specific germ is the probable exciting cause 

 of the disease. 



